The present invention relates to a process for preparing phycoerythrin from Bangia atropurpurea or Porphyra angusta filaments.
Natural pigment proteins from plants are safe when used in food and drink. The pigments are stable in mild heat, and acidic or basic solutions. Therefore they can be utilized in food and cosmetics as coloring agent. In additional, the pure form of the pigment can be used in fluorescent labeling of antibodies that were applied as diagnostic agent in immunological, clinical, cell biological and biochemical research.
Phycocyanin and phycoerythrin are two currently used natural pigment proteins, and have been applied in many fields. As the major raw material for phycocyanin is easy-growing blue-green algae such as Spirulina and Microcystis and a large number of methods of algae cultivation and phycocyanin preparation therefrom have been developed, the supply of phycocyanin does not cause a problem. However, the quantity of phycoerythrin is still few and the price is high due to the shortage of raw material available and the difficulty in processing for the commercial production of phycoerythrin.
Most of the phycoerythrin is extracted from red algae thalli such as Porphyra and Ceramium, and only a little amount of phycoerythrin are extracted from Porphyridium, which is now available from tank cultivation.
Although increasing amount of wild red algae and cultivated Porphyra are utilized as raw material for phycoerythrin, most of them contain a high gel content, making the extraction of phycoerythrin from them be very difficult, especially for dried algae. Furthermore, the quantity and quality of wild algae are apt to be influenced by the seasons and the ambient temperature. These elements make the production of phycoerythrin from wild and cultivated Porphyra even more difficult.
Extracting phycoerythrin from Porphyridium also has its difficulties, because the collection of single-cell is usually labor-intensive as well as time-consuming and the soluble polysaccharide secreted during the cultivation of algae will deter the cell collection and influence the extraction of phycoerythrin.